Great Hornbill
Encyclopedia
The Great Hornbill also known as Great Indian Hornbill or Great Pied Hornbill, is one of the larger members of the hornbill
family. Great Hornbills are found in the forests of Nepal
, India
, the Malay Peninsula
and Sumatra
, Indonesia
. Their impressive size and colour have made them important in many tribal cultures and rituals. The Great Hornbill is long-lived, living for nearly 50 years in captivity. They are predominantly frugivorous although they are opportunists and will prey on small mammals, reptiles and birds.
The Great Hornbill is a large bird, 95–120 cm (38–47 in) long, with a 152 cm (60 in) wingspan and a weight of 2.15–4 kg (4.7-8.8 lbs). It is the heaviest, but not the longest, Asian hornbill. The most prominent feature of the hornbill is the bright yellow and black casque on top of its massive bill. The casque appears U-shaped when viewed from the front and the top is concave with two ridges along the sides that form points in the front, a reference to which is made in the Latin species epithet bicornis. The casque is hollow and serves no known purpose although they are believed to be the result of sexual selection
. Male hornbills have been known to indulge in aerial casque butting, with birds striking each other in flight. Females are smaller than males and have bluish-white instead of red eyes although the orbital skin is pinkish. Like other hornbills, they have prominent "eyelashes". The back of the casque is reddish in females while the underside of the front and back of the casque is black in males. The male spreads the preen gland secretion which is yellow onto the primaries and bill to give them the bright yellow colour. The commissure
of the beak is black and has a serrated and worn edge with age. The wing beats are heavy and the sound produced by birds in flight can be heard from a distance. The sound produced has been likened to the puffing of a steam locomotive starting up. The flight involves stiff flaps followed by glides with the fingers splayed and upcurled. They are sometimes known to fly at great height over forests.
The species was formerly broken into subspecies cavatus from the Western Ghats
, nominate form from the sub-Himalayan forests is sometimes named as subspecies homrai. The subspecies from Sumatra has sometimes been considered as cristatus. The variation across populations is mainly in size, with Himalayan birds being larger than the those from further south and the species is now usually considered monotypic.
Like other members of the hornbill family, they have highly pneumatized bones, with hollow air cavities extending to the tips of their wing bones. This anatomical feature was noted by Richard Owen
who dissected a specimen at the Zoological Society of London that died in 1833.
In Thailand the home range
s of males was found to be about 3.7 km² during the breeding season and about 14.7 km² during the non-breeding season.
are particularly important as a food sources. Vitex altissima has been noted as another important species. They also forage on lipid-rich fruits of the Lauraceae and Myristicaceae families such as Persea
, Alseodaphne
and Myristica. They obtain the water that they need entirely from their diet of fruits. They are important dispersers of many forest tree species. They will also eat small mammals, birds, small reptiles and insects. It has been observed that lion-tailed macaque
s forage alongside these hornbills.
They forage along branches, moving along by hopping, looking for insects, nestling birds, small lizards, tearing up bark and examining them. Prey are caught, tossed in the air and swallowed. A rare squirrel, the Travancore flying squirrel Petinomys fuscocapillus has been noted in the diet of the species while Collared Scops Owl Otus bakkamoena, Jungle Owlet Glaucidium radiatum and Grey-fronted Green Pigeon Treron pompadora have been noted as prey birds in the Western Ghats
.
The Great Hornbills form monogamous pair bonds and live in small groups of 2-40 individuals. Group courtship displays involving up to 20 birds have been observed.
Female hornbills build nests in hollows of large tree trunks and the opening is sealed with a plaster made up mainly of feces. She remains imprisoned in her nest until the chicks are semi-developed relying on the male to bring her food. During this period the female undergoes a complete moult. The young squabs are devoid of feathers and appear very plump. She is fed by her mate through a slit in the seal. The clutch consists of one or two eggs she incubates for 38–40 days. The female voids faeces through the nest slit and young follow the same nest sanitation behaviour after they are two weeks old. Once the female emerges out of the nest, it is sealed again by the chicks.
The young birds have no trace of a casque. After the second year, the front extremity separates from the culmen and in the third year becomes a transverse crescent with the two edges growing outwards and upwards while the anterior gets broader to equal the hind end in width. The full development takes five years.
In captivity hornbills eat fruits and meat and a healthy diet is made up in most part, by fruit and some source of protein. A few have been tamed in captivity but hornbill behavior in captivity is described as high-strung.
Captive specimens may bask in the sun with outstretched wings.
on the IUCN Red List
of Threatened Species. It is listed on Appendix I of CITES. Declines in population have been noted in many areas such as Cambodia. Molecular approaches to the study of their population diversity have been attempted.
Tribals threaten the Great Indian Hornbills with their desire for its various parts. The beaks and head are used in charms and the flesh is believed to be medicinal. The squabs are considered a delicacy. Tribesmen in parts of northeastern India and Borneo use their feathers for head-dresses, and their skulls are often worn as decorations. Their flesh is considered unfit for eating by the Nagas with the belief that they produce sores on their feet as in the bird. When dancing with the feathers of the hornbill, the avoid eating vegetables as it is also believed to produce the same sores on the feet. Conservation programmes have attempted to provide tribes with feathers from captive hornbills and ceramic casques to substitute natural ones.
The hornbills is called "homrai" in Nepal (giving the name of that subspecies) and "banrao" both meaning "King of the forest".
A Great Hornbill by the name of William (pictured) is the symbol of the Bombay Natural History Society
. Hornbill house is the name of their headquarters building. Sir Norman Kinnear
described William as follows in the obituary of W S Millard
:
“Every visitor to the Society's room in Apollo Street will remember the great Indian Hornbill, better known as the "office canary" which lived in a cage behind Millard's chair in Phipson & Co.'s office for 26 years and died in 1920. It is said its death was caused by swallowing a piece of wire, but in the past "William" had swallowed a lighted cigar without ill effects and I for my part think that the loss of his old friend was the principal cause."
The Great Hornbill is the State bird of Chin state
in Myanmar
, and Kerala
and Arunachal in India
.
Hornbill
Hornbills are a family of bird found in tropical and subtropical Africa, Asia and Melanesia. They are characterized by a long, down-curved bill which is frequently brightly-colored and sometimes has a casque on the upper mandible. Both the common English and the scientific name of the family...
family. Great Hornbills are found in the forests of Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, the Malay Peninsula
Malay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
and Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. Their impressive size and colour have made them important in many tribal cultures and rituals. The Great Hornbill is long-lived, living for nearly 50 years in captivity. They are predominantly frugivorous although they are opportunists and will prey on small mammals, reptiles and birds.
Description
Sexual selection
Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...
. Male hornbills have been known to indulge in aerial casque butting, with birds striking each other in flight. Females are smaller than males and have bluish-white instead of red eyes although the orbital skin is pinkish. Like other hornbills, they have prominent "eyelashes". The back of the casque is reddish in females while the underside of the front and back of the casque is black in males. The male spreads the preen gland secretion which is yellow onto the primaries and bill to give them the bright yellow colour. The commissure
Commissure
A commissure is the place where two things are joined. The term is used especially in the fields of anatomy and biology.In anatomy, commissure refers to a bundle of nerve fibers that cross the midline at their level of origin or entry .* The most common usage of the term refers to the brain's...
of the beak is black and has a serrated and worn edge with age. The wing beats are heavy and the sound produced by birds in flight can be heard from a distance. The sound produced has been likened to the puffing of a steam locomotive starting up. The flight involves stiff flaps followed by glides with the fingers splayed and upcurled. They are sometimes known to fly at great height over forests.
The species was formerly broken into subspecies cavatus from the Western Ghats
Western Ghats
The Western Ghats, Western Ghauts or the Sahyādri is a mountain range along the western side of India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The Western Ghats block rainfall to the Deccan...
, nominate form from the sub-Himalayan forests is sometimes named as subspecies homrai. The subspecies from Sumatra has sometimes been considered as cristatus. The variation across populations is mainly in size, with Himalayan birds being larger than the those from further south and the species is now usually considered monotypic.
Like other members of the hornbill family, they have highly pneumatized bones, with hollow air cavities extending to the tips of their wing bones. This anatomical feature was noted by Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
who dissected a specimen at the Zoological Society of London that died in 1833.
Distribution and habitat
The distribution of the species is fragmented over its range in South and Southeast Asia. In South Asia they are found in a few forest areas in the Western Ghats and in the forests along the Himalayas. Their distribution extends into Thailand, Burma, Malaya and Sumatra. Their habitat is dense old growth (unlogged) forests in hilly regions. They appear to be dependent on large stretches of forest unlike many of the smaller hornbills.In Thailand the home range
Home range
Home range is the area where an animal lives and travels in. It is closely related to, but not identical with, the concept of "territory".The concept that can be traced back to a publication in 1943 by W. H. Burt, who constructed maps delineating the spatial extent or outside boundary of an...
s of males was found to be about 3.7 km² during the breeding season and about 14.7 km² during the non-breeding season.
Food and feeding
Great Hornbills are usually seen in small parties with larger groups sometimes aggregating at fruit trees. A congregation of 150 to 200 birds has been recorded in southeastern Bhutan. In the wild, the Great Hornbill's diet consists mainly of fruit. FigsFicus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
are particularly important as a food sources. Vitex altissima has been noted as another important species. They also forage on lipid-rich fruits of the Lauraceae and Myristicaceae families such as Persea
Persea
Persea is a genus of about 150 species of evergreen trees belonging to the laurel family, Lauraceae. The best-known member of the genus is the avocado, P. americana, widely cultivated in subtropical regions for its large, edible fruit.-Overview:...
, Alseodaphne
Alseodaphne
Alseodaphne is a genus of plant in family Lauraceae....
and Myristica. They obtain the water that they need entirely from their diet of fruits. They are important dispersers of many forest tree species. They will also eat small mammals, birds, small reptiles and insects. It has been observed that lion-tailed macaque
Lion-tailed Macaque
The lion-tailed macaque is an Old World monkey that is endemic to the Western Ghats of South India.-Physical Characteristics:...
s forage alongside these hornbills.
They forage along branches, moving along by hopping, looking for insects, nestling birds, small lizards, tearing up bark and examining them. Prey are caught, tossed in the air and swallowed. A rare squirrel, the Travancore flying squirrel Petinomys fuscocapillus has been noted in the diet of the species while Collared Scops Owl Otus bakkamoena, Jungle Owlet Glaucidium radiatum and Grey-fronted Green Pigeon Treron pompadora have been noted as prey birds in the Western Ghats
Western Ghats
The Western Ghats, Western Ghauts or the Sahyādri is a mountain range along the western side of India. It runs north to south along the western edge of the Deccan Plateau, and separates the plateau from a narrow coastal plain along the Arabian Sea. The Western Ghats block rainfall to the Deccan...
.
Breeding
During the breeding season they become very vocal. They make loud duets. These calls begin with a loud "kok" about once a second given by the male and joined in by a female. The pair then calls in unison turning into a rapid mixture of roars and barks. They prefer mature forests for nesting. Large, tall and old trees, particularly emergents that rise above the canopy appeared to be preferred for nesting.The Great Hornbills form monogamous pair bonds and live in small groups of 2-40 individuals. Group courtship displays involving up to 20 birds have been observed.
Female hornbills build nests in hollows of large tree trunks and the opening is sealed with a plaster made up mainly of feces. She remains imprisoned in her nest until the chicks are semi-developed relying on the male to bring her food. During this period the female undergoes a complete moult. The young squabs are devoid of feathers and appear very plump. She is fed by her mate through a slit in the seal. The clutch consists of one or two eggs she incubates for 38–40 days. The female voids faeces through the nest slit and young follow the same nest sanitation behaviour after they are two weeks old. Once the female emerges out of the nest, it is sealed again by the chicks.
The young birds have no trace of a casque. After the second year, the front extremity separates from the culmen and in the third year becomes a transverse crescent with the two edges growing outwards and upwards while the anterior gets broader to equal the hind end in width. The full development takes five years.
Roosting
Roost sites are used regularly and birds will arrive punctually at sunset from long distances, following the same routes each day. Several tall trees in the vicinity may be used, the birds choosing the highest branches with little foliage. They jockey for positions until late at dusk. When sleeping they draw their neck back and the bill is held upwards at an angle.In captivity
Very few hornbills are held in captivity and few of them breed well. The females at the nests are extremely easy to capture and wild caught birds are female biased. Breeding them in captivity has been notoriously difficult with fewer than a dozen successful attempts. Their extreme selectivity for mates and the long and strong pair bonds make them difficult to maintain for breeding.In captivity hornbills eat fruits and meat and a healthy diet is made up in most part, by fruit and some source of protein. A few have been tamed in captivity but hornbill behavior in captivity is described as high-strung.
Captive specimens may bask in the sun with outstretched wings.
Conservation status
Due to habitat loss and hunting in some areas, the Great Hornbill is evaluated as Near ThreatenedNear Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
of Threatened Species. It is listed on Appendix I of CITES. Declines in population have been noted in many areas such as Cambodia. Molecular approaches to the study of their population diversity have been attempted.
In culture
The hornbills is called "homrai" in Nepal (giving the name of that subspecies) and "banrao" both meaning "King of the forest".
Use as a symbol
Bombay Natural History Society
The Bombay Natural History Society, founded on 15 September 1883, is one of the largest non-governmental organizations in India engaged in conservation and biodiversity research. It supports many research efforts through grants, and publishes the Journal of the Bombay Natural History Society. Many...
. Hornbill house is the name of their headquarters building. Sir Norman Kinnear
Norman Boyd Kinnear
Sir Norman Boyd Kinnear was a Scottish zoologist and ornithologist.Kinnear was the son of the wealthy Edinburgh architect Charles George Hood Kinnear and came from the same banking family as Sir William Jardine.While studying at Trinity College, Glenalmond, he worked as a voluntary assistant at...
described William as follows in the obituary of W S Millard
Walter Samuel Millard
Walter Samuel Millard was a British entrepreneur and naturalist who was honorary secretary of the Bombay Natural History Society and editor of the Journal of the Bombay Natural History Society from 1906 to 1920, co-author of the classic, Some Beautiful Indian Trees, and the driving force behind...
:
“Every visitor to the Society's room in Apollo Street will remember the great Indian Hornbill, better known as the "office canary" which lived in a cage behind Millard's chair in Phipson & Co.'s office for 26 years and died in 1920. It is said its death was caused by swallowing a piece of wire, but in the past "William" had swallowed a lighted cigar without ill effects and I for my part think that the loss of his old friend was the principal cause."
The Great Hornbill is the State bird of Chin state
Chin State
Chin State is a state located in western Burma . The Chin State is bordered by Rakhine State in the south, Bangladesh in south-west, Sagaing Division and Magway Division in the east, Indian state of Manipur in the north and Indian state of Mizoram in the west. The Chin ethnic group make up the...
in Myanmar
Myanmar
Burma , officially the Republic of the Union of Myanmar , is a country in Southeast Asia. Burma is bordered by China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest, and the Andaman Sea on the south....
, and Kerala
Kerala
or Keralam is an Indian state located on the Malabar coast of south-west India. It was created on 1 November 1956 by the States Reorganisation Act by combining various Malayalam speaking regions....
and Arunachal in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
.
Other sources
- Kannan,R (1994) Ecology and Conservation of the Great Pied Hornbill (Buceros bicornis) in the Western Ghats of southern India. Ph.D. Thesis, University of Arkansas, Fayetteville.
- Kannan,Ragupathy (1994) Conservation ecology of the Great Hornbill in the Western Ghats, southern India. OBC Bull. 19:13.
- Poonswad, P. 1995. Nest site characteristics of four sympatric species of hornbills in Khao Yai National Park, Thailand. Ibis 137: 183-191.
- Poonswad, P. and A. Tsuji. 1994. Ranges of males of the Great Hornbill (Buceros bicornis), Brown Hornbill (Ptilolaemus tickelli) and Wreathed Hornbill (Rhyticeros undulatus) in Khao Yai National Park, Thailand. Ibis 136: 79-86.
External links
- Great Hornbill videos, photos & sounds on the Internet Bird Collection
- CITES Guide (PDF)
- Great Horbill : Saint Louis Zoo